As described more fully in the above-identified application, a ski which is released from a ski boot on a slope can engage in free flight and, at high speeds, poses a danger to other skiers. For this reason it has been proposed to provide a ski with an automatic brake which is retained in its inoperative position by an application of the ski boot against a ski, e.g. against a spring force tending to bias an actuator into an operative position. The actuator may be engaged by the toe or heel of the ski boot when the latter is properly received in the ski binding.
The actuator is generally provided with one or two brake elements which are constituted as blades and swing from their inoperative positions in which they permit ordinary skiing into operative positions in which they engage the ground and prevent free flight of the ski when the actuator is released by the ski boot.
Such devices are termed hereinafter generically as ski brakes and generally have an actuator which is biased under a primary spring force from the inoperative position toward the operative position, in a mounting plate which can be affixed to the upper surface of the ski.
In one such ski brake, which is mounted behind the binding in a bearing or journal arrangement, the pivot axis includes an acute angle with the longitudinal axis of the ski and the basic spring force is generated by a torsion spring which acts upon a blade-like brake element.
In another conventional construction, leaf springs are secured at their forward ends to the ski and at their rearward ends tend to bend upwardly when they are unloaded. Upon loading by the ski boot, these spring elements are urged toward the upper surface of the ski to swing the blades into positions generally parallel to the ski edges as described in Austrian Pat. No. 299,036. Other ski brakes are described in Austrian Pat. No. 280,867 and 210,804 although these devices are somewhat more remote from the present invention than the prior-art devices described above and hence require no detailed discussion. Austrian Pat. No. 305,844 describes a ski brake having a spring which, upon release of an actuator, rotates a shaft extending transverse to the ski, about the shaft axis to bring the blade into play.
German published application (Offenlegungsschrift) No. 2,417,279 describes a ski brake which is mounted by a support plate on the upper surface of the ski. In one recess of this support plate, a round-cross-section wire is pivotally journaled and is formed as a pivot shaft. One end of the circular-cross-section wire forms a brake spur while another region of the wire is bent into a retaining hoop, the free end of the hoop being formed as a second shaft journaled in a further recess of the support plate. It is important in this construction that the two journaling recesses in the support plate be exactly parallel, a factor which increases the fabrication cost and causes differences with respect to mounting or operation if not fulfilled. These two journalling recesses impart an elastic prestress to the circular-section wire so that the braking spur automatically springs into the operative position when the wire is released by the ski boot.